refactored broad range of the application, split files, modularized calendar and file views, centralized bottom sheets and clipboard handling, and implemented unit test coverage

lib/view/pages/talk/widgets/chat_tile.dart

@@ -2,13 +2,13 @@ import 'dart:async';
 
 import 'package:flutter/material.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
-import 'package:jiffy/jiffy.dart';
 
 import '../../../../api/marianumcloud/talk/actions/talk_actions.dart';
 import '../../../../api/marianumcloud/talk/chat/rich_object_string_processor.dart';
 import '../../../../api/marianumcloud/talk/room/get_room_response.dart';
 import '../../../../api/marianumcloud/talk/set_read_marker/set_read_marker.dart';
 import '../../../../api/marianumcloud/talk/set_read_marker/set_read_marker_params.dart';
+import '../../../../extensions/date_time.dart';
 import '../../../../model/account_data.dart';
 import '../../../../state/app/modules/chat/bloc/chat_bloc.dart';
 import '../../../../state/app/modules/chat_list/bloc/chat_list_bloc.dart';
@@ -96,7 +96,7 @@ class _ChatTileState extends State<ChatTile> {
         ],
       ),
       subtitle: Text(
-        '${Jiffy.parseFromMillisecondsSinceEpoch(widget.data.lastMessage.timestamp * 1000).fromNow()}: '
+        '${DateTime.fromMillisecondsSinceEpoch(widget.data.lastMessage.timestamp * 1000).formatRelative()}: '
         '${RichObjectStringProcessor.parseToString(widget.data.lastMessage.message.replaceAll("\n", " "), widget.data.lastMessage.messageParameters)}',
         overflow: TextOverflow.ellipsis,
       ),